Introduction to the Ginkgoales

the ginkgos

What plant may cure Alzheimer's disease, increase circulation, tastes like almonds and smells like rancid butter? This plant is none other than Ginkgo biloba. Ginkgo extracts have played a crucial role in Chinese herbal medicine for many centuries. Only recently has western medicine began to seriously study the medicinal uses of ginkgo. It is amazing that this plant might not even exist today had it not been for the Buddhist monks in Japan and China who cultivated it in their temple gardens and adopted it as a sacred tree.

Although Ginkgo biloba is the only extant species of ginkgos today, many ginkgo relatives have been found in the fossil record. The Ginkgoales are a group of gymnosperms that date back to the Permian. The group is thought to be more closely related to conifers than to any other gymnosperms. During the middle Jurassic, the Ginkgoales experienced a great increase in species and reached their maximum diversity during the Cretaceous with several species identifiable in what is now Asia, Europe and North America. During the Paleocene, Ginkgoalean diversity was reduced to a single polymorphic species referred to as Gingko adiantoides. This species is almost indistinguishable from the extant Ginkgo biloba.

The modern-day Ginkgo biloba has a very distinct appearance characterized by its fan-shaped leaves. In fact, the Japanese sometimes call this species I-cho, "tree with leaves like a duck's foot." It can grow up to 30 meters tall and can live for a millenium. It is also well-known for its unique seeds, which have long been used as a food source in Asia. The smell of a great mass of rotting seeds can also be overpowering. In the horticultural literature, it is variously referred to as "disagreeable," "evil," "offensive," "disgusting," "repulsive," and "abominable," and is often compared to the odor of vomit. It is due to the malodorous chemical compound butyric acid, whcih is found in the integument of the seed; it is the same compound that gives rancid butter its "distinctive" smell.

Ginkgo biloba is a highly adaptable plant that can grow in almost any temperate or Mediterranean climate. It is also resistant to pollution and pests. These attributes have made the male ginkgos very popular in cities.

Click on the buttons below to find out more about the Ginkgoales.

The article from the Journal of the American Medical Association about Ginkgo biloba and Alzheimer's: [ full text, abstract ]

For general ginkgo information, including propogation, see Cor Kwant's Ginkgo Page.

Link to butyric acid information courtesy of the National Institute of Standards and Technology.

Most images in the Ginkgoales exhibit provided courtesy Virtual Foliage at the University of Wisconsin-La Crosse, and by Nan Crystal Arens. Images should not be reused without their permission.

Sun, G., 1993, Ginkgo Coriacea Florin from Lower Cretaceous of Huolinhe, Northeastern Nei Monggol, China. Palaeontographica, Abt. 8, V. 230: 159-168.

Taylor, Thomas N. and Edith L., 1993, The Biology of Evolution of Fossil Plants, Prentice Hall, New Jersey, pp. 636-43.

Del Tredici, P., 1989, Ginkgos and multituberculates: evolutionary interactions in the Tertiary, Biosystems 21-22: 327-337.